Portable paraffin baths for administering heat therapy to parts of the human body are well known. One such device which has been in commercial use for a considerable period of time is sold under the trademark THERABATH. This unit includes a tank in which the paraffin wax is retained. When the bath is being employed daily in home use, it is desirable to replace the wax approximately once a month, and then to thoroughly clean the tank. When the unit is being used in a clinic or other physical therapy department, it is recommended that the wax applied to the patients body be disgarded after each application.
In order to remove the wax from the prior art system, referred to above, it is recommended that the wax first be cooled to permit it to solidify. Then, to remove the solid block, it is necessary to slightly re-heat the wax to thereby loosen it from the tank walls. Any wax that still remains on the walls is blotted out with paper towels, and if necessary, the bath is again heated to loosen any remaining solidified wax. After removal of all of the wax, it is recommended by the manufacturer that a soapy cloth first be used to clean the tank, and that a dry cloth then be used to complete the cleaning operation.
From the above explanation, it should be apparent that the cleaning operation is somewhat cumbersome In fact, if the individual attempting to clean the tank is the one being treated for an affliction such as arthritis or bursitis of the hands, the cleaning operation itself can provide a very painful experience.
It should also be pointed out that the above-discussed prior art tank weighs approximately 6 to 8 pounds, without the block of paraffin in it. With approximately 3 pounds of paraffin the unit weighs between 9 to 11 pounds. In either event the portability of the unit would be enhanced if its weight were reduced.
U.S. Pat. No. 3,157,774, issued to Moore et al, discloses a portable paraffin bath wherein the paraffin is retained in an inner container and indirectly heated by a heat exchange liquid, such as water. The bath disclosed in Moore is somewhat complex; including two drainage systems; one for removing the treatment material (e.g. paraffin), and the other for removing the heat exchange liquid (e.g. water). Moreover, once the treatment liquid has been removed from the inner container, a manual cleaning operation, similar to that required in connection with the Therabath system, needs to be employed.
U.S. Pat. No. 4,149,536, issued to Villard, although relating to a paraffin wax treatment system, employs a spray gun for applying the treatment fluid to the part of the body requiring treatment. This is significantly different from, and employs an entirely different structural arrangement of elements than the present invention.
U.S. Pat. No. 2,463,329, issued to Stansbury, also discloses a therapeutic bath employing paraffin In this construction the metal vessel 20 in which the paraffin is retained is a fixed part of the unit, i.e. it is not removable from its supporting structure. In fact, the invention disclosed in this patent is directed predominately to the paraffin drainage system associated with the vessel.
U.S. Pat. No. 2,396,578, issued to Kittel et al, is referenced herein because it does relate generally to an apparatus for heating and melting plastic or similar material. This apparatus employs an indirect heating system similar to that employed in the apparatus disclosed in the earlier-discussed Moore et al U.S. Pat. No. (3,157,774), but does not relate to a heat therapy system of the type designed to accommodate part of the human body.
The invention described hereinafter is particularly well suited for heat therapy applications.